Composite Cam Assembly for Foldable Hinge Wear and Strength

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Solution Overview

Problem

Existing cam assemblies in foldable smartphones face challenges in maintaining high wear resistance while ensuring sufficient strength, as the wear-resistant layers on stainless steel cams wear out quickly due to frequent friction during folding and unfolding.

Innovation Solution

The proposed cam assembly incorporates a wear-resistant material for the cams and a frame with embedded fasteners and a connector, which provides axial, circumferential, and transverse support, enhancing both wear resistance and structural integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a wear-resistant layer is disposed on the outer surface of a stainless steel cam, then wear resistance is improved, but the strength of the cam deteriorates when the wear-resistant layer is completely worn

Engineering Contradiction:
Improvewear resistanceVSAvoidcam strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The cam body is constructed as a composite structure combining stainless steel material and aluminum alloy material. The stainless steel portion provides wear resistance at the friction surface, while the aluminum alloy portion provides structural strength and weight reduction. This composite material approach resolves the contradiction by integrating both wear-resistant and strong materials into a single cam component.

Inventive Principle:
Principle #40Composite materials

2Weight of moving object

If the wear-resistant layer is made small in thickness to reduce weight, then wear resistance is improved initially, but the layer wears out quickly under frequent friction

Engineering Contradiction:
Improvecam weightVSAvoidwear resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

Instead of using a thin wear-resistant coating on a heavy stainless steel cam, the invention uses a composite cam where the wear-resistant stainless steel material is integrated as part of the cam body structure. This provides sufficient wear resistance without requiring a thick coating, thereby maintaining low weight while ensuring long-term durability under frequent friction.

Inventive Principle:
Principle #40Composite materials

3Reliability

If a cam is made entirely of wear-resistant material, then wear resistance is improved, but the strength and structural integrity of the cam deteriorates

Engineering Contradiction:
Improvewear resistanceVSAvoidstructural integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The cam is designed as a composite structure where different materials are strategically combined: stainless steel material is used for the wear-resistant outer portion that contacts other components, while aluminum alloy material is used for the inner structural portion that requires strength but not direct contact. This composite approach ensures both wear resistance and structural integrity are optimized.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP4199486B1CAM assembly, folding mechanism, terminal device, and manufacturing method for CAM assembly
Publication Date: 2025.04.30 HONOR DEVICE CO LTD
  • EP4199486B1 patent drawingFigure 1a
  • EP4199486B1 patent drawingFigure 1b
  • EP4199486B1 patent drawingFigure 2

AI summary

This application provides a cam assembly, a folding mechanism, terminal device, and a method for manufacturing a cam assembly, and relates to the field of terminals. The cam assembly includes a cam body and a frame. The cam body includes a first cam and a second cam that are oppositely disposed, and a connection body; materials of both the first cam and the second cam include a wear-resistant material; and a first concave portion cooperating with the cam structure is disposed at one end of the cam body. The frame includes a first fastener and a second fastener that are oppositely disposed, and a connector; the first fastener is embedded into the first cam, and the second fastener is embedded into the second cam; extension directions of the first fastener in the first cam include at least the axial direction and the circumferential direction, and extension directions of the second fastener in the second cam include at least the axial direction and the circumferential direction; and the connector is embedded into the connection body. According to this application, wear resistance of the cam assembly can be improved while relatively high strength of the cam assembly is ensured.